Dense YSZ Laminates Obtained by Aqueous Tape Casting and Calendering

Abstract

Dense electrolytes and flawless laminated YSZ electrolytes can be produce combining aqueous tape casting and constrained calendering. During calendering two or more layers are laminated continuously and the edges (entering and final) are not sealed at the same time avoiding air bubbles to trap between the layers. In this study constrained calendering laminates showed adequate adhesion between layers, and almost 20% thickness reduction after sintering as well as high green and sintered densities.

Critical analysis of aqueous tape casting, sintering, and characterization of planar Yttria‐Stabilized Zirconia electrolytes for SOFC

“…These binders usually have low polymer content associated with high viscosity, are sensitive to moisture after drying, and demand the use of considerable amounts of plasticizers. More recently, based on the vast amount of data for alumina aqueous slurries, tape casting of water‐based YSZ slurries has been investigated and advanced, being shown to be viable, aiming mostly its application in SOFCs …”

“…ESC consists in fabricating the electrolyte by tape casting and sintering, and then applying the electrodes by other techniques such as screen-printing or spin coating. 6 In ASC, the anode and electrolyte layers are obtained by successive tape casting and co-sintering. 7 Tape casting is a well-established low cost ceramic forming process and presents wide industrial use in the fabrication of several components, such as electronics substrates, multilayered and functionally graded ceramics, and solid oxide fuel cells components.…”

“…More recently, based on the vast amount of data for alumina aqueous slurries, tape casting of water-based YSZ slurries has been investigated and advanced, being shown to be viable, aiming mostly its application in SOFCs. 6,12,[21][22][23] Slurry composition is one of the most significant factors in tape casting, which influences the characteristics of green and, consequently, sintered tapes. Slurries for tape casting should present high solid loading, in order to improve particle network strength, as well as adequate viscosity and be well dispersed in order to produce green tapes with good handling strength and excellent homogeneity.…”

“…8 Meanwhile, it has become common to add a lamination step in the processing of green tapes, in order to improve electrolyte density and to work around problems involving microstructure heterogeneities and low green density that may arise during the slurry preparation and the tape casting process. 6,[30][31][32] However, this step represents more variables to be controlled and introduces the chance for more problems in the overall production of ceramic films, such as delamination. 33,34 The characteristics of sintered tapes will also depend on the sintering conditions, such as heating rate, dwell temperature and time, and applied loading during sintering.…”

“…Moreover, in this design, SOFCs can be fabricated as electrolyte‐supported cells (ESC) or anode‐supported cells (ASC) by conventional tape casting or co‐tape casting. ESC consists in fabricating the electrolyte by tape casting and sintering, and then applying the electrodes by other techniques such as screen‐printing or spin coating . In ASC, the anode and electrolyte layers are obtained by successive tape casting and co‐sintering …”